הרב דב בער ממזריטש

Dov Ber ben Avraham of Mezeritch, also known as the Maggid of Mezeritch or Mezeritcher Maggid, was a disciple of Rabbi Israel ben Eliezer, the founder of Hasidic Judaism, and was chosen as his successor to lead the early movement. Dov Ber is regarded as the first systematic exponent of the mystical philosophy underlying the teachings of the Baal Shem Tov, and through his teaching and leadership, the main architect of the movement.